Light emitting diode component

Abstract

In a lighting package, a printed circuit board supports at least one light emitting die. A light transmissive cover is disposed over the at least one light emitting die. A phosphor is disposed on or inside of the light transmissive dome-shaped cover. The phosphor outputs converted light responsive to irradiation by the at least one light emitting die. An encapsulant substantially fills an interior volume defined by the light-transmissive cover and the printed circuit board.

Description

[0001]This application is a continuation of application Ser. No. 11 / 312,268 filed Dec. 20, 2005 which is a continuation-in-part of application Ser. No. 10 / 831,862 filed Apr. 26, 2004 and since issued as U.S. Pat. No. 7,224,000 which is a continuation-in-part of International Application number PCT / US2003 / 027363 with an international filing date of Aug. 29, 2003 first published Mar. 11, 2004 as International Publication no. WO 2004 / 021461 A2, which claims the benefit of U.S. Provisional Application Ser. No. 60 / 407,426 filed on Aug. 30, 2001 This application is also a continuation-in-part of application Ser. No. 10 / 909,564 filed Nov. 2, 2004 and since issued as U.S. Pat. No. 7,768,189.[0002]This application incorporates by reference the content of application Ser. No. 11 / 312,268, which has published as US 2006-0097245 A1. This application incorporates by reference the content of application Ser. No. 10 / 831,862, which has issued as U.S. Pat. No. 7,224,000 and has published as US 2005-0...

AI Technical Summary

Benefits of technology

This patent describes various light emitting packages and methods for making them. These packages have a printed circuit board that supports a light emitting die, such as a LED, and a light transmissive cover that is attached to the printed circuit board. An encapsulant is used to fill the interior volume of the cover and encapsulate the die. These packages can provide efficient and effective lighting, and can be used in various applications such as in lighting fixtures or vehicle lights. The present invention offers improvements in design, materials, and production processes for these light emitting packages.

Problems solved by technology

One issue with light emitting diode components or packages relates to light output intensity.

Early light emitting diodes had low light output intensities and were generally not competitive with incandescent and fluorescent light sources.

Another issue with light emitting diode components and packages relates to ruggedness.

Commonly used packaging techniques, such as bonding of the dice to lead frames, can produce relatively fragile light emitting packages.

Moreover, light emitting diode components and packages tend to be complex.

Multiple chip packages generally further increase complexity.

The complexity of multiple chip packages such as those of Lowery and Baretz can adversely impact manufacturability, reliability, and manufacturing costs.

Another issue with typical light emitting diode packages and components is operating lifetime.

Performance of packages employing phosphor wavelength conversion of ultraviolet or short-wavelength visible light typically degrades over time due to discoloration or other degradation of the encapsulant or other materials caused by the ultraviolet or short-wavelength visible light irradiation.

Another issue with typical light emitting diode packages is plug-in capability with lighting fixtures.

Such plug-in fixture compatibility is, however, hampered by the typically high voltage and / or high frequency electrical power supplied by such fixtures, which is not conducive to powering low-voltage light emitting diode devices.

Another issue with using light emitting diode packages for illumination is light output quality.

When light emitting diode packages employ several light emitting chips so as to produce high light intensity, a problem arises in that the output consists of several approximate point light sources corresponding to the several chips.

This pixelated spatial distribution of light is problematic for illumination applications.

Spectral light output quality can also be an issue when using light emitting diode packages for white illumination.

Obtaining white light or substantially white light with a desired (usually high) CRI value in a commercially practical manner is difficult.

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